To achieve permanent, intense colors with corresponding fastness properties, so-called oxidative dyes are used. Said dyes usually contain oxidative dye precursors, so-called developer components and coupler components. The developer components join together or couple with one or more coupler components to form, under the influence of oxidants or atmospheric oxygen, the actual dyes per se. Indeed, the oxidative dyes are exemplified by outstanding, long-lasting color results. To achieve natural-looking colors, however, a mixture from a larger number of oxidative dye precursors (ODP) must normally be used; in many cases, partially-oxidizing dyes are still used to create the tinting effect.
Most of the oxidative dyes used for stabilizing the dye precursors during storage and to accelerate the reaction during oxidative application have an alkali pH value, which is set with alkalizing agents such as alkanolamines, ammonia or inorganic bases.
To produce the dye, the alkali coloring component is usually mixed with a hydrous hydrogen peroxide solution to form a homogeneous creme or a homogeneous gel, and then applied immediately to the hair to be dyed. This dye mixture remains on the hair for a period of from about 5 to about 60 minutes, until the oxidative formation of the dye on the hair is complete. The dye mixture is then washed out.
The aforementioned oxidative precursors (OPC) and alkalizing agents are usually worked into the hair in a cosmetically suitable carrier, such as a creme, for example. The carrier guarantees a homogeneous distribution and an adequate dwell time of the hair dye on the hair.
The disadvantage is the complex manufacture of such a creme. The fusing of the fat components and the emulsification process requires a high amount of energy. The subsequent cooling process consumes large quantities of cooling water.
A further disadvantage is that a creme has to be packaged in a relatively complex manner. Due to their higher viscosity, cremes are incapable of flowing and cannot be transferred from a storage bottle into the application bottle, in which the hydrogen peroxide solution has already been placed, simply by tipping. Instead, the alkali dye cremes are packed primarily in flexible aluminum tubes, packaging material with high energy and raw material consumption.
A higher viscosity of the dye creme is a further disadvantage in terms of producing the application mixture. The alkali dye creme is mixed with the developer preparation by hand. The most homogeneous application mixture possible is required to achieve an effective color result. It must be possible to produce said mixture within the shortest possible time. This is because the oxidation dye precursors start to react as soon as they come into contact with the hydrogen peroxide and the atmospheric oxygen. The fastest possible mixture is achieved most readily if dye creme and developer preparation are as fluid as possible. Conversely, the application mixture itself should be more viscose so that it remains on the hair without dripping.